/* Copyright 2017 The TensorFlow Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/

#include "tensorflow/compiler/xla/shape_tree.h"

#include <memory>

#include "tensorflow/compiler/xla/shape_util.h"
#include "tensorflow/compiler/xla/test.h"
#include "tensorflow/compiler/xla/xla_data.pb.h"
#include "tensorflow/tsl/platform/test_benchmark.h"

namespace xla {
namespace {

class ShapeTreeTest : public ::testing::Test {
 protected:
  ShapeTreeTest() {
    array_shape_ = ShapeUtil::MakeShape(F32, {42, 42, 123});
    tuple_shape_ =
        ShapeUtil::MakeTupleShape({array_shape_, array_shape_, array_shape_});
    nested_tuple_shape_ = ShapeUtil::MakeTupleShape(
        {array_shape_, ShapeUtil::MakeTupleShape({array_shape_, array_shape_}),
         ShapeUtil::MakeTupleShape(
             {ShapeUtil::MakeTupleShape({array_shape_, array_shape_}),
              array_shape_})});
  }

  void TestShapeConstructor(const Shape& shape, int expected_num_nodes);
  void TestInitValueConstructor(const Shape& shape, int expected_num_nodes);

  // An array shape (non-tuple).
  Shape array_shape_;

  // A three element tuple shape.
  Shape tuple_shape_;

  // A nested tuple shape of the following form: (a, (c, d), ((e, f), g))
  Shape nested_tuple_shape_;
};

TEST_F(ShapeTreeTest, DefaultConstructor) {
  ShapeTree<int> int_tree;
  EXPECT_TRUE(ShapeUtil::IsEmptyTuple(int_tree.shape()));

  ShapeTree<bool> bool_tree;
  EXPECT_TRUE(ShapeUtil::IsEmptyTuple(bool_tree.shape()));
}

void ShapeTreeTest::TestShapeConstructor(const Shape& shape,
                                         int expected_num_nodes) {
  ShapeTree<int> int_tree(shape);
  int num_nodes = 0;
  int_tree.ForEachElement([&num_nodes](const ShapeIndex& /*index*/, int data) {
    EXPECT_EQ(0, data);
    ++num_nodes;
  });
  EXPECT_EQ(expected_num_nodes, num_nodes);

  ShapeTree<bool> bool_tree(shape);
  num_nodes = 0;
  bool_tree.ForEachElement(
      [&num_nodes](const ShapeIndex& /*index*/, bool data) {
        EXPECT_EQ(false, data);
        ++num_nodes;
      });
  EXPECT_EQ(expected_num_nodes, num_nodes);
}

TEST_F(ShapeTreeTest, ShapeConstructor) {
  TestShapeConstructor(array_shape_, 1);
  TestShapeConstructor(tuple_shape_, 4);
  TestShapeConstructor(nested_tuple_shape_, 10);
}

void ShapeTreeTest::TestInitValueConstructor(const Shape& shape,
                                             int expected_num_nodes) {
  ShapeTree<int> tree(shape, 42);
  int num_nodes = 0;
  tree.ForEachElement([&num_nodes](const ShapeIndex& /*index*/, int data) {
    EXPECT_EQ(42, data);
    ++num_nodes;
  });
  EXPECT_EQ(expected_num_nodes, num_nodes);

  num_nodes = 0;
  tree.ForEachMutableElement(
      [&num_nodes](const ShapeIndex& /*index*/, int* data) {
        EXPECT_EQ(42, *data);
        *data = num_nodes;
        ++num_nodes;
      });
  EXPECT_EQ(expected_num_nodes, num_nodes);

  num_nodes = 0;
  tree.ForEachElement([&num_nodes](const ShapeIndex& /*index*/, int data) {
    EXPECT_EQ(num_nodes, data);
    ++num_nodes;
  });
  EXPECT_EQ(expected_num_nodes, num_nodes);
}

TEST_F(ShapeTreeTest, InitValueConstructor) {
  TestInitValueConstructor(array_shape_, 1);
  TestInitValueConstructor(tuple_shape_, 4);
  TestInitValueConstructor(nested_tuple_shape_, 10);
}

TEST_F(ShapeTreeTest, EmptyTupleMustHaveNoLeaves) {
  ShapeTree<int> shape_tree{ShapeUtil::MakeTupleShape({})};
  EXPECT_EQ(0, shape_tree.leaf_count());
}

TEST_F(ShapeTreeTest, NestedEmptyTuple) {
  Shape shape(
      ShapeUtil::MakeTupleShape({ShapeUtil::MakeTupleShape({}), array_shape_}));
  ShapeTree<int> shape_tree{shape};
  EXPECT_EQ(ShapeUtil::GetLeafCount(shape), shape_tree.leaf_count());
}

TEST_F(ShapeTreeTest, ArrayShape) {
  ShapeTree<int> shape_tree{array_shape_};
  *shape_tree.mutable_element({}) = 42;
  EXPECT_EQ(42, shape_tree.element({}));
  *shape_tree.mutable_element({}) = 123;
  EXPECT_EQ(123, shape_tree.element({}));

  EXPECT_TRUE(ShapeUtil::Compatible(array_shape_, shape_tree.shape()));

  // Test the copy constructor.
  ShapeTree<int> copy{shape_tree};
  EXPECT_EQ(123, copy.element({}));

  // Mutate the copy, and ensure the original doesn't change.
  *copy.mutable_element({}) = 99;
  EXPECT_EQ(99, copy.element({}));
  EXPECT_EQ(123, shape_tree.element({}));

  // Test the assignment operator.
  copy = shape_tree;
  EXPECT_EQ(123, copy.element({}));
}

TEST_F(ShapeTreeTest, TupleShape) {
  ShapeTree<int> shape_tree{tuple_shape_};
  *shape_tree.mutable_element({}) = 1;
  *shape_tree.mutable_element({0}) = 42;
  *shape_tree.mutable_element({1}) = 123;
  *shape_tree.mutable_element({2}) = -100;
  EXPECT_EQ(1, shape_tree.element({}));
  EXPECT_EQ(42, shape_tree.element({0}));
  EXPECT_EQ(123, shape_tree.element({1}));
  EXPECT_EQ(-100, shape_tree.element({2}));

  EXPECT_TRUE(ShapeUtil::Compatible(tuple_shape_, shape_tree.shape()));

  // Sum all elements in the shape.
  int sum = 0;
  shape_tree.ForEachElement(
      [&sum](const ShapeIndex& /*index*/, int data) { sum += data; });
  EXPECT_EQ(66, sum);

  // Test the copy constructor.
  ShapeTree<int> copy{shape_tree};
  EXPECT_EQ(1, copy.element({}));
  EXPECT_EQ(42, copy.element({0}));
  EXPECT_EQ(123, copy.element({1}));
  EXPECT_EQ(-100, copy.element({2}));

  // Write zero to all data elements.
  shape_tree.ForEachMutableElement(
      [](const ShapeIndex& /*index*/, int* data) { *data = 0; });
  EXPECT_EQ(0, shape_tree.element({}));
  EXPECT_EQ(0, shape_tree.element({0}));
  EXPECT_EQ(0, shape_tree.element({1}));
  EXPECT_EQ(0, shape_tree.element({2}));
  EXPECT_EQ(1, copy.element({}));
  EXPECT_EQ(42, copy.element({0}));
  EXPECT_EQ(123, copy.element({1}));
  EXPECT_EQ(-100, copy.element({2}));

  // Test the assignment operator.
  copy = shape_tree;
  EXPECT_EQ(0, copy.element({}));
  EXPECT_EQ(0, copy.element({0}));
  EXPECT_EQ(0, copy.element({1}));
  EXPECT_EQ(0, copy.element({2}));
}

TEST_F(ShapeTreeTest, NestedTupleShape) {
  ShapeTree<int> shape_tree{nested_tuple_shape_};
  *shape_tree.mutable_element({0}) = 42;
  *shape_tree.mutable_element({1, 1}) = 123;
  *shape_tree.mutable_element({2, 0, 1}) = -100;
  EXPECT_EQ(42, shape_tree.element({0}));
  EXPECT_EQ(123, shape_tree.element({1, 1}));
  EXPECT_EQ(-100, shape_tree.element({2, 0, 1}));

  EXPECT_TRUE(ShapeUtil::Compatible(nested_tuple_shape_, shape_tree.shape()));

  // Test the copy constructor.
  ShapeTree<int> copy{shape_tree};
  EXPECT_EQ(42, copy.element({0}));
  EXPECT_EQ(123, copy.element({1, 1}));
  EXPECT_EQ(-100, copy.element({2, 0, 1}));

  // Mutate the copy, and ensure the original doesn't change.
  *copy.mutable_element({0}) = 1;
  *copy.mutable_element({1, 1}) = 2;
  *copy.mutable_element({2, 0, 1}) = 3;
  EXPECT_EQ(1, copy.element({0}));
  EXPECT_EQ(2, copy.element({1, 1}));
  EXPECT_EQ(3, copy.element({2, 0, 1}));
  EXPECT_EQ(42, shape_tree.element({0}));
  EXPECT_EQ(123, shape_tree.element({1, 1}));
  EXPECT_EQ(-100, shape_tree.element({2, 0, 1}));

  // Test the assignment operator.
  copy = shape_tree;
  EXPECT_EQ(42, copy.element({0}));
  EXPECT_EQ(123, copy.element({1, 1}));
  EXPECT_EQ(-100, copy.element({2, 0, 1}));
}

TEST_F(ShapeTreeTest, InvalidIndexingTuple) {
  ShapeTree<int> shape_tree{tuple_shape_};
#ifndef NDEBUG
  EXPECT_DEATH(shape_tree.element({4}), "");
#endif
}

TEST_F(ShapeTreeTest, InvalidIndexingNestedTuple) {
  ShapeTree<int> shape_tree{nested_tuple_shape_};
#ifndef NDEBUG
  EXPECT_DEATH(shape_tree.element({0, 0}), "");
#endif
}

TEST_F(ShapeTreeTest, ShapeTreeOfNonCopyableType) {
  ShapeTree<std::unique_ptr<int>> shape_tree{tuple_shape_};
  EXPECT_EQ(shape_tree.element({2}).get(), nullptr);
  *shape_tree.mutable_element({2}) = std::make_unique<int>(42);
  EXPECT_EQ(*shape_tree.element({2}), 42);
}

TEST_F(ShapeTreeTest, CopySubtreeFromArrayShape) {
  // Test CopySubtreeFrom method for a single value copied between array-shaped
  // ShapeTrees.
  ShapeTree<int> source(array_shape_);
  *source.mutable_element(/*index=*/{}) = 42;
  ShapeTree<int> destination(array_shape_, 123);

  EXPECT_EQ(destination.element(/*index=*/{}), 123);
  destination.CopySubtreeFrom(source, /*source_base_index=*/{},
                              /*target_base_index=*/{});
  EXPECT_EQ(destination.element(/*index=*/{}), 42);
}

TEST_F(ShapeTreeTest, FullCopySubtreeFromTupleShape) {
  // Test CopySubtreeFrom method for a copy of all elements from one
  // tuple-shaped ShapeTree to another.
  ShapeTree<int> source(tuple_shape_);
  *source.mutable_element(/*index=*/{}) = 10;
  *source.mutable_element(/*index=*/{0}) = 11;
  *source.mutable_element(/*index=*/{1}) = 12;
  *source.mutable_element(/*index=*/{2}) = 13;

  ShapeTree<int> destination(tuple_shape_, 0);

  destination.CopySubtreeFrom(source, /*source_base_index=*/{},
                              /*target_base_index=*/{});
  EXPECT_EQ(destination.element(/*index=*/{}), 10);
  EXPECT_EQ(destination.element(/*index=*/{0}), 11);
  EXPECT_EQ(destination.element(/*index=*/{1}), 12);
  EXPECT_EQ(destination.element(/*index=*/{2}), 13);
}

TEST_F(ShapeTreeTest, SingleElementCopySubtreeFromTupleShape) {
  // Test CopySubtreeFrom method for a copy of a single element from one
  // tuple-shaped ShapeTree to another.
  ShapeTree<int> source(tuple_shape_);
  *source.mutable_element(/*index=*/{}) = 10;
  *source.mutable_element(/*index=*/{0}) = 11;
  *source.mutable_element(/*index=*/{1}) = 12;
  *source.mutable_element(/*index=*/{2}) = 13;

  ShapeTree<int> destination(tuple_shape_, 0);

  destination.CopySubtreeFrom(source, /*source_base_index=*/{0},
                              /*target_base_index=*/{1});
  EXPECT_EQ(destination.element(/*index=*/{}), 0);
  EXPECT_EQ(destination.element(/*index=*/{0}), 0);
  EXPECT_EQ(destination.element(/*index=*/{1}), 11);
  EXPECT_EQ(destination.element(/*index=*/{2}), 0);
}

TEST_F(ShapeTreeTest, CopySubtreeIntoNestedShape) {
  // Test CopySubtreeFrom method for a copy of a tuple-shaped ShapeTree into a
  // nested-tuple-shaped ShapeTree.
  ShapeTree<int> source(
      ShapeUtil::MakeTupleShape({array_shape_, array_shape_}));
  *source.mutable_element(/*index=*/{}) = 10;
  *source.mutable_element(/*index=*/{0}) = 11;
  *source.mutable_element(/*index=*/{1}) = 12;

  ShapeTree<int> destination(nested_tuple_shape_, 0);

  destination.CopySubtreeFrom(source, /*source_base_index=*/{},
                              /*target_base_index=*/{2, 0});

  EXPECT_EQ(destination.element(/*index=*/{}), 0);
  EXPECT_EQ(destination.element(/*index=*/{0}), 0);
  EXPECT_EQ(destination.element(/*index=*/{1}), 0);
  EXPECT_EQ(destination.element(/*index=*/{1, 0}), 0);
  EXPECT_EQ(destination.element(/*index=*/{1, 1}), 0);
  EXPECT_EQ(destination.element(/*index=*/{2}), 0);
  EXPECT_EQ(destination.element(/*index=*/{2, 0}), 10);
  EXPECT_EQ(destination.element(/*index=*/{2, 0, 0}), 11);
  EXPECT_EQ(destination.element(/*index=*/{2, 0, 1}), 12);
  EXPECT_EQ(destination.element(/*index=*/{2, 1}), 0);
}

TEST_F(ShapeTreeTest, CopySubtreeFromNestedShape) {
  // Test CopySubtreeFrom method for a copy from a nested-tuple-shape.
  ShapeTree<int> source(nested_tuple_shape_, 42);
  *source.mutable_element(/*index=*/{1}) = 10;
  *source.mutable_element(/*index=*/{1, 0}) = 11;
  *source.mutable_element(/*index=*/{1, 1}) = 12;

  ShapeTree<int> destination(
      ShapeUtil::MakeTupleShape({array_shape_, array_shape_}), 0);

  destination.CopySubtreeFrom(source, /*source_base_index=*/{1},
                              /*target_base_index=*/{});

  EXPECT_EQ(destination.element(/*index=*/{}), 10);
  EXPECT_EQ(destination.element(/*index=*/{0}), 11);
  EXPECT_EQ(destination.element(/*index=*/{1}), 12);
}

TEST_F(ShapeTreeTest, OperatorEquals) {
  {
    ShapeTree<int> a(array_shape_, 123);
    ShapeTree<int> b(array_shape_, 42);
    ShapeTree<int> c(array_shape_, 42);
    EXPECT_FALSE(a == b);
    EXPECT_TRUE(a != b);
    EXPECT_TRUE(b == c);
  }
  {
    ShapeTree<int> a(tuple_shape_);
    *a.mutable_element(/*index=*/{}) = 10;
    *a.mutable_element(/*index=*/{0}) = 11;
    *a.mutable_element(/*index=*/{1}) = 12;

    ShapeTree<int> b(tuple_shape_);
    *b.mutable_element(/*index=*/{}) = 10;
    *b.mutable_element(/*index=*/{0}) = 42;
    *b.mutable_element(/*index=*/{1}) = 11;

    ShapeTree<int> c(tuple_shape_);
    *c.mutable_element(/*index=*/{}) = 10;
    *c.mutable_element(/*index=*/{0}) = 42;
    *c.mutable_element(/*index=*/{1}) = 11;

    EXPECT_FALSE(a == b);
    EXPECT_TRUE(a != b);
    EXPECT_TRUE(b == c);
    EXPECT_FALSE(b != c);
  }
}

TEST_F(ShapeTreeTest, ConstructWithPointerToShape) {
  // Construct a ShapeTree using a pointer to a shape, rather than a reference
  // to a shape.  This constructor is an optimization to let us avoid
  // constructing and destroying temporary shapes when we have many ShapeTrees.
  ShapeTree<int> t(&nested_tuple_shape_, 42);
  int num_nodes = 0;
  t.ForEachElement([&num_nodes](const ShapeIndex& /*index*/, int data) {
    EXPECT_EQ(42, data);
    ++num_nodes;
  });
  EXPECT_EQ(10, num_nodes);
}

TEST_F(ShapeTreeTest, CopyWithPointerToShape) {
  ShapeTree<int> source(&nested_tuple_shape_, 0);
  ShapeTree<int> dest(source);
  EXPECT_EQ(&dest.shape(), &nested_tuple_shape_);
}

TEST_F(ShapeTreeTest, CopyAssignWithPointerToShape) {
  ShapeTree<int> source(&nested_tuple_shape_, 0);
  ShapeTree<int> dest;
  dest = source;
  EXPECT_EQ(&dest.shape(), &nested_tuple_shape_);
}

TEST_F(ShapeTreeTest, IterateSimple) {
  ShapeTree<int> t(nested_tuple_shape_, 42);
  int num_nodes = 0;
  for (auto index_to_data : t) {
    EXPECT_EQ(42, index_to_data.second);
    ++num_nodes;
  }
  EXPECT_EQ(10, num_nodes);
}

TEST_F(ShapeTreeTest, ConstIterate) {
  const ShapeTree<int> t(nested_tuple_shape_, 42);
  int num_nodes = 0;
  for (const auto& index_to_data : t) {
    EXPECT_EQ(42, index_to_data.second);
    ++num_nodes;
  }
  EXPECT_EQ(10, num_nodes);
}

TEST_F(ShapeTreeTest, IterateAndMutate) {
  ShapeTree<int> t(nested_tuple_shape_, 42);
  int i = 0;
  for (auto& index_to_data : t) {
    EXPECT_EQ(42, index_to_data.second);
    if (i == 1) {
      index_to_data.second = 98;
    }
    ++i;
  }
  (*t.begin()).second = 78;
  EXPECT_EQ(78, (*t.begin()).second);
  i = 0;
  for (auto& index_to_data : t) {
    if (i == 0) {
      EXPECT_EQ(78, index_to_data.second);
    } else if (i == 1) {
      EXPECT_EQ(98, index_to_data.second);
    } else {
      EXPECT_EQ(42, index_to_data.second);
    }
    ++i;
  }
  EXPECT_EQ(78, (*t.begin()).second);
  EXPECT_EQ(98, (*std::next(t.begin())).second);
}

TEST_F(ShapeTreeTest, IterateOrder) {
  ShapeTree<int> t(nested_tuple_shape_, 42);
  std::vector<ShapeIndex> v;
  v.reserve(t.leaf_count());
  for (auto index_to_data : t) {
    v.push_back(index_to_data.first);
  }
  EXPECT_EQ(v, (std::vector<ShapeIndex>{{},
                                        {0},
                                        {1},
                                        {1, 0},
                                        {1, 1},
                                        {2},
                                        {2, 0},
                                        {2, 0, 0},
                                        {2, 0, 1},
                                        {2, 1}}));
}

TEST_F(ShapeTreeTest, ReverseIterateOrder) {
  ShapeTree<int> t(nested_tuple_shape_, 42);
  std::vector<ShapeIndex> v;
  v.reserve(t.leaf_count());
  for (auto it = t.rbegin(); it != t.rend(); ++it) {
    v.push_back(it->first);
  }
  EXPECT_EQ(v, (std::vector<ShapeIndex>{
                   {2, 1},
                   {2, 0, 1},
                   {2, 0, 0},
                   {2, 0},
                   {2},
                   {1, 1},
                   {1, 0},
                   {1},
                   {0},
                   {},
               }));
}

// Ensures that we can find an element at an index that we know ahead of time to
// be occupied in a 'ShapeTree' via the 'find' API.
TEST_F(ShapeTreeTest, Find) {
  ShapeTree<int> t(nested_tuple_shape_, 42);
  auto found = t.find({1, 0});
  EXPECT_NE(found, t.end());
  // The found key must be the same key we searched for.
  EXPECT_EQ(found->first, ShapeIndex({1, 0}));
  // The 'ShapeTree' has 42 at every position.
  EXPECT_EQ(found->second, 42);
}

// Ensures that we can find an element at an index that we know ahead of time to
// be occupied in a 'const ShapeTree' via the 'find' API.
TEST_F(ShapeTreeTest, ConstFind) {
  const ShapeTree<int> t(nested_tuple_shape_, 42);
  auto found = t.find({1, 0});
  EXPECT_NE(found, t.end());
  // The found key must be the same key we searched for.
  EXPECT_EQ(found->first, ShapeIndex({1, 0}));
  // The 'ShapeTree' has 42 at every position.
  EXPECT_EQ(found->second, 42);
}

TEST_F(ShapeTreeTest, IterateOrderLeaves) {
  ShapeTree<int> t(nested_tuple_shape_, 42);
  std::vector<ShapeIndex> v;
  const auto& leaves = t.leaves();
  v.reserve(t.leaf_count());
  for (auto index_to_data : leaves) {
    v.push_back(index_to_data.first);
  }
  EXPECT_EQ(v, (std::vector<ShapeIndex>{
                   {0}, {1, 0}, {1, 1}, {2, 0, 0}, {2, 0, 1}, {2, 1}}));
}

TEST_F(ShapeTreeTest, ReverseIterateOrderLeaves) {
  ShapeTree<int> t(nested_tuple_shape_, 42);
  std::vector<ShapeIndex> v;
  v.reserve(t.leaf_count());
  for (auto it = t.leaf_rbegin(); it != t.leaf_rend(); ++it) {
    v.push_back(it->first);
  }
  EXPECT_EQ(v, (std::vector<ShapeIndex>{
                   {2, 1},
                   {2, 0, 1},
                   {2, 0, 0},
                   {1, 1},
                   {1, 0},
                   {0},
               }));
}

void BM_Construct(::testing::benchmark::State& state) {
  const int depth = state.range(0);
  const int fan_out = state.range(1);

  Shape shape = ShapeUtil::MakeShape(F32, {32, 64, 128});
  for (int i = 0; i < depth; ++i) {
    std::vector<xla::Shape> shapes(fan_out, shape);
    shape = ShapeUtil::MakeTupleShape(shapes);
  }

  for (auto s : state) {
    ShapeTree<int> shape_tree(shape);
  }
}

void BM_ConstructUnowned(::testing::benchmark::State& state) {
  const int depth = state.range(0);
  const int fan_out = state.range(1);

  Shape shape = ShapeUtil::MakeShape(F32, {32, 64, 128});
  for (int i = 0; i < depth; ++i) {
    std::vector<xla::Shape> shapes(fan_out, shape);
    shape = ShapeUtil::MakeTupleShape(shapes);
  }

  for (auto s : state) {
    ShapeTree<int> shape_tree(&shape);
  }
}

void BM_Copy(::testing::benchmark::State& state) {
  const int depth = state.range(0);
  const int fan_out = state.range(1);

  Shape shape = ShapeUtil::MakeShape(F32, {32, 64, 128});
  for (int i = 0; i < depth; ++i) {
    std::vector<xla::Shape> shapes(fan_out, shape);
    shape = ShapeUtil::MakeTupleShape(shapes);
  }

  ShapeTree<int> shape_tree(shape);
  for (auto s : state) {
    ShapeTree<int> copy = shape_tree;
    tsl::testing::DoNotOptimize(copy);
  }
}

void BM_Move(::testing::benchmark::State& state) {
  const int depth = state.range(0);
  const int fan_out = state.range(1);

  Shape shape = ShapeUtil::MakeShape(F32, {32, 64, 128});
  for (int i = 0; i < depth; ++i) {
    std::vector<xla::Shape> shapes(fan_out, shape);
    shape = ShapeUtil::MakeTupleShape(shapes);
  }

  ShapeTree<int> shape_tree(shape);
  for (auto s : state) {
    ShapeTree<int> copy = std::move(shape_tree);
    shape_tree = std::move(copy);
  }
}

void BM_ForEach(::testing::benchmark::State& state) {
  const int depth = state.range(0);
  const int fan_out = state.range(1);

  Shape shape = ShapeUtil::MakeShape(F32, {32, 64, 128});
  for (int i = 0; i < depth; ++i) {
    std::vector<xla::Shape> shapes(fan_out, shape);
    shape = ShapeUtil::MakeTupleShape(shapes);
  }

  ShapeTree<int> shape_tree(shape);
  for (auto s : state) {
    shape_tree.ForEachMutableElement([](const ShapeIndex& index, int* data) {
      tsl::testing::DoNotOptimize(index);
    });
  }
}

void BM_Iterate(::testing::benchmark::State& state) {
  const int depth = state.range(0);
  const int fan_out = state.range(1);

  Shape shape = ShapeUtil::MakeShape(F32, {32, 64, 128});
  for (int i = 0; i < depth; ++i) {
    std::vector<xla::Shape> shapes(fan_out, shape);
    shape = ShapeUtil::MakeTupleShape(shapes);
  }

  ShapeTree<int> shape_tree(shape);
  for (auto s : state) {
    for (auto& iter : shape_tree) {
      tsl::testing::DoNotOptimize(iter.second);
    }
  }
}

#define BENCHMARK_WITH_ARGS(name) \
  BENCHMARK(name)->ArgPair(2, 8)->ArgPair(1, 1000)

BENCHMARK_WITH_ARGS(BM_Construct);
BENCHMARK_WITH_ARGS(BM_ConstructUnowned);
BENCHMARK_WITH_ARGS(BM_Copy);
BENCHMARK_WITH_ARGS(BM_Move);
BENCHMARK_WITH_ARGS(BM_ForEach);
BENCHMARK_WITH_ARGS(BM_Iterate);

}  // namespace
}  // namespace xla
